Management server and operation method thereof and server system

ABSTRACT

A management server includes a storage unit, a sub-server and a load balancing unit. The storage unit stores a datum. The sub-server is corresponded to the storage unit and obtains the datum from the storage unit according to a request signal. The load balancing unit is coupled to the sub-server and receives the request signal from the client. The load balancing unit distributes the request signal to the corresponding sub-server according to a request number of the request signal. The management server outputs the datum obtained by the sub-server from the storage unit according to the request number.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan PatentApplication Serial Number 104103835, filed on. Feb. 5, 2015, the fulldisclosure of which is incorporated herein by reference.

BACKGROUND Technical Field

This disclosure generally relates to a server and an operation methodthereof and, more particularly, to a management server and an operationmethod thereof and a server system.

Related Art

Since the advances in the internet technology, many electronic products(such as clients) can connect to the server through the Internet andsearch the data stored in the database of the server. The server maysearch the data in the database according to a message content providedfrom the client, and send the data, obtained from the database, back tothe corresponding client. As the number of clients increases, themessage contents provided from the clients increase, and the servicerequirements provided by the server may also increase.

Owing to the more the clients and the more the requirement for searchingthe message contents, the more the data may store in the database. Inthis case, the time for searching the corresponding data in the databaseand sending the data back to the client may be spend much longer, thatmeans, the client may waste much more time on waiting the feedback ofthe server. Therefore, the processing efficiency of the server and thespeed for searching the data and sending the data back to the clientneeds improvement.

SUMMARY

The disclosure provides a management server and an operation methodthereof and a server system, thereby balancing the amount of theconnection to balance the efficiency of the system and decrease the timefor searching the data.

The disclosure provides a management server. The data management serverincludes a storage unit, a sub-server and a load balancing unit. Thestorage unit stores a datum. The sub-server corresponds to the storageunit and obtains the datum from the storage unit according to a requestsignal, wherein the request signal is generated by a client and therequest signal has a request number. The load balancing unit is coupledto the sub-server and receives the request signal from the client. Theload balancing unit distributes a request signal to the correspondingsub-server according to the request number. The management serveroutputs the datum obtained by the sub-server from the storage unitaccording to the request number.

The disclosure further provides an operation method of a managementserver. The operation method of the management server includes thefollowing steps: receiving a request signal from a client, wherein therequest signal has a request number; distributing the request number toa sub-server according to the request number; obtaining a datum by thesub-server from a storage unit according to the request number, whereinthe storage unit is corresponding to the sub-server; and outputting thedatum according to the request number.

The disclosure further provides a server system. The server systemincludes a client and a management server. The client generates arequest signal, wherein the request signal has a request number. Themanagement server includes a storage unit, a sub-server and a loadbalancing unit. The storage unit stores a datum. The sub-servercorresponds to the storage unit and obtains the datum from the storageunit according to the request signal. The load balancing unit isconnected to the client and coupled to the sub-server, the loadbalancing unit receives the request signal from the client, anddistributes a request signal to the corresponding sub-server accordingto the request number. The management server outputs the datum obtainedby the sub-server from the storage unit according to the request number.

According to the management server and the operation method thereof andthe server system in the exemplary embodiments, the load balancing unitdistributes the request signal to the corresponding sub-server accordingto the request number of the request signal, such that the sub-serverobtains the datum from the corresponding storage unit, and then themanagement server (i.e. the load balancing unit or the sub-server)outputs the datum from the corresponding storage unit according to therequest number. Therefore, the amount of the connection may be balancedto balance an efficiency of the system and decrease a time for searchingthe data.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the exemplary embodiments believed to be novel and theelements and/or the steps characteristic of the exemplary embodimentsare set forth with particularity in the appended claims. The Figures arefor illustration purposes only and are not drawn to scale. The exemplaryembodiments, both as to organization and method of operation, may bestbe understood by reference to the detailed description which followstaken in conjunction with the accompanying drawings in which:

FIG. 1 shows a schematic diagram of the management server according to afirst exemplary embodiment of the disclosure;

FIG. 2 shows a flowchart of the operation method of the managementserver according to a second exemplary embodiment of the disclosure;

FIG. 3 shows a flowchart of the operation method of the managementserver according to a third exemplary embodiment of the disclosure;

FIG. 4 shows a schematic diagram of the server system according to afourth exemplary embodiment of the disclosure; and

FIG. 5 shows a schematic diagram of the server system according to afifth exemplary embodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following description is of the best-contemplated mode of carryingout the invention. This description is made for the purpose ofillustration of the general principles of the invention and should notbe taken in a limiting sense. The scope of the invention is bestdetermined by reference to the appended claims.

Moreover, the terms “include”, “contain”, and any variation thereof areintended to cover a non-exclusive inclusion. Therefore, a process,method, object, or device that includes a series of elements not onlyincludes these elements, but also includes other elements not specifiedexpressly, or may include inherent elements of the process, method,object, or device. If no more limitations are made, an element limitedby “include a/an . . . ” does not exclude other same elements existingin the process, the method, the article, or the device which includesthe element.

FIG. 1 shows a schematic diagram of the management server according to afirst exemplary embodiment of the disclosure. The management server 100includes a plurality of storage units 110_1 to 110_N, a plurality ofsub-servers 120_1 to 120_N and a load balancing unit 130.

Each of the storage units 110_1 to 110_N stores a datum, and N is apositive integer greater than 1. The storage units 110_1 to 110_N maybe, for example, a form for storing data, such as cache with entity orblock of a database without entity.

The database is used to store all the data of the management server 100and unify all the data stored in the storage units 110_1 to 110_N. Whena new datum is written in or updated, the database may distribute thedatum to each of the storage units 110_1 to 110_N. In the embodiment,the datum stored in each of the storage units 110_1 to 110_N may be, forexample, a portion of all the data stored in the database. That is, allthe data stored in the database may be synchronized and uniformlydistributed to each of the storage units 110_1 to 110_N. For example, ifthe quantity of the storage units 110_1 to 110_N is ten, the dataquantity stored in the each of the storage units 110_1 to 110_10respectively is the 1/10 data quantity of the database, or all the dataof the database may be divided into ten blocks to store in thecorresponding storage unit. The other embodiments are similar to theprevious ones, and the description may be referred to the previousembodiment. The datum stored in each of the storage units 110_1 to 110_Nmay also been updated to be all the same, part of the same, or alldifferent according to the using requirement.

Each of the sub-servers 1201 to 120_N respectively corresponds to thestorage units 10_1˜110_N and obtains the datum from the storage unitsaccording to a request signal. In the embodiment, each of thesub-servers 120_1 to 120_N may be, for example, an entity or a virtualserver device. Wherein, owing to the each of the sub-servers 120_1 to120_N is respectively corresponds to the each of the storage units 110_1to 110_N, the sub-servers may obtains the datum from the storage unitsone by one.

For example, the sub-server 120_1 corresponds to the storage unit 110_1,and the sub-server 120_1 may obtain the datum requested from the storageunit 110_1 according to the corresponding request signal. The sub-server120_2 corresponds to the storage unit 110_2, and the sub-server 120_2may obtain the datum requested from the storage unit 110_2 according thecorresponding request signal. The other embodiments are similar to theprevious ones, and the description may be referred to the previousembodiment. In FIG. 1, the sub-servers 120_1 to 120_N are separated fromthe storage units 110_1 to 110_N, and it is not limited to thedisclosure. The storage units 110_1 to 110_N may also be built-in thesub-servers 120_1 to 120_N.

Additionally, the sub-servers 120_1 to 120_N may connect to the databaseperiodically or non-periodically so as to update the datum stored in thestorage units 110_1˜110_N at any time. Or, when a new data is added,deleted or updated in the database, the sub-servers 120_1 to 120_N mayconnect to the database immediately so as to update the datum stored inthe storage units 110_1˜110_N at any time.

The load balancing unit 130 is coupled to the sub-servers 120_1 to 120_Nand receives the request signal from a client. The request signal isgenerated by the client, and the request signal may include a requestnumber. The request number may be, for example, a unique identification(UID) which formed as MAC address or formed as random string by Englishwords, numerals or symbols.

When the load balancing unit 130 receives the request signal, the loadbalancing unit 130 can also obtain the request number in the requestsignal and distributes the request signal to the correspondingsub-servers 120_1 to 120_N according to the request number.

In the embodiment, a manner for distributing the request number is thatrequest number is analyzed by using a mathematics method such asfunctional operation, and the foremost number or the last number of theanalyzed request number is used.

For example, it is assumed that the quantity of the sub-servers is ten,such as the sub-servers 120_1˜120_10. When the foremost number or thelast number of the request number obtained by the load balancing unit130 is “1”, the load balancing unit 130 may distribute the requestsignal corresponding to the request number “1” to the correspondingsub-server 120_1. When the foremost number or the last number of therequest number obtained by the load balancing unit 130 is “2”, the loadbalancing unit 130 may distribute the request signal corresponding tothe request number “2” to the corresponding sub-server 120_2.

The other embodiments that the foremost number or the last number of therequest number obtained by the load balancing unit 130 is “3” to “9” aresimilar to the previous ones, and the description may be referred to theprevious embodiment. When the foremost number or the last number of therequest number obtained by the load balancing unit 130 is “0”, the loadbalancing unit 130 may distribute the request signal corresponding tothe request number “0” to the corresponding sub-server 120_10.

Then, the sub-servers 120_1 to 120_N obtain the datum from thecorresponding storage units 110_1 to 110_N according to the receivedrequest signal. Afterward, the management server 100 outputs theabove-mentioned datum to the client according to the request signal,such that the client may obtain the datum requested.

Further, in one embodiment, after the sub-servers 120_1 to 120_N obtainthe datum from the corresponding storage units 110_1 to 110_N, thesub-servers 120_1 to 120_N may feed the datum obtained from the storageunits 110_1 to 110_N back to the load balancing unit 130, such that themanagement server 100 outputs the above-mentioned datum to the clientthrough the load balancing unit 130.

In another embodiment, the sub-servers 120_1 to 120_N may directlyoutput the datum obtained from the storage units 110_1 to 110_N to theclient. That is, the management server 100 may output theabove-mentioned datum to the client through the sub-servers 120_1 to120_N, so as to increase the speed for sending the datum back.

According to the above-mentioned description, the load balancing unit130 distributes the request signal to the corresponding sub-servers120_1 to 120_N and then the sub-servers 120_1 to 120_N only need toobtain the datum from the corresponding storage units 110_1 to 110_N.Additionally, the datum stored in the storage units may be classifiedand stored in advance, such that after the sub-servers 120_1 to 120_Nreceive the request signal, sub-servers 120_1 to 120_N may obtain thedatum from the corresponding storage units 110_1 to 110_N quickly.Therefore, the time for searching the datum may be decrease effectively.

Further, when the sub-servers 120_1 to 120_N receive the request signal,the sub-servers 120_1 to 120_N may capture a predetermined requestnumber stored in the storage units 110_1 to 110_N, and then compare therequest number of the request signal with the predetermined requestnumber, so as to determine whether the request signal received by thesub-servers 120_1 to 120_N is legal.

When the request number is equal to the predetermined request number, itmeans that the request signal is legal, the sub-servers 120_1˜120_Nperform the corresponding process according to the request signal, i.e.the sub-servers 120_1 to 120_N obtain the datum from the storage units110_1 to 110_N. If the request number is not equal to the predeterminedrequest number, it means that the request signal is illegal, and thenthe sub-servers 120_1 to 120_N do not perform the corresponding process.Afterward, the sub-servers 120_1 to 120_N may wait for the next requestsignal distributed by the load balancing unit 130 and then perform thefollowing process. Therefore, an efficiency decrease of the managementserver 100 related to an illegal request signal can be avoided.

In the embodiment of FIG. 1, the quantity of the sub-servers 1201 to120_N and the storage units 110_1 to 110_N is greater than one, and itis not limited to the disclosure. The quantity of the sub-server and thestorage unit may also respectively be one, and the embodiment of thesub-server and the storage unit may be referred to the above-mentioneddescription, and the description is omitted.

Additionally, the quantity of the request signal and the request numberthereof and the predetermined request number is one, and it is notlimited to the disclosure. The quantity of the request signal and therequest number thereof and the predetermined request number may also betwo or more than two. For example, when the quantity of the requestsignal and the request number thereof is two, the quantity of thepredetermined request number should be two. When the quantity of therequest signal and the request number thereof is three, the quantity ofthe predetermined request number should be three. The other embodimentsare similar to the previous ones, and the description may be referred tothe previous embodiment.

Otherwise, when the quantity of the request signal is two, the tworequest signals may be outputted by the different clients. The otherembodiments are similar to the previous ones, and the description may bereferred to the previous embodiment. In other embodiments, multiple ofthe request signals and the request numbers thereof and thepredetermined request numbers may be referred to the description of theabove-mentioned embodiment, and the description is omitted.

Moreover, the request signal may has, for example, one request number,and it is not limited to the disclosure. The request signal may alsohas, for example, two or more than two request numbers at the same time.The quantity of the request number may correspond to the quantity of thepredetermined request number. For example, when the quantity of therequest number is two, the quantity of the predetermined request numberis two. When the quantity of the request number is three, the quantityof the predetermined request number is three. The other embodiments aresimilar to the previous ones, and the description may be referred to theprevious embodiment. The embodiments of the request signals includingtwo or more than two request numbers at the same time may be referred tothe description of the above-mentioned embodiment, and the descriptionis omitted.

Additionally, in the above-mentioned embodiment, the request number isanalyzed by using the functional operation to distribute the requestsignal, and it is not limited to the disclosure. The request number maybe analyzed by using the other manners similar to the functionaloperation to distribute the request signal, and the other manners foranalyzing the request number are within the scope of the disclosure. Theoperation of the other manners may be referred to the above-mentioneddescription, and the description is omitted.

According to the above-mentioned description, it may sum up an operationmethod of a management server. FIG. 2 shows a flowchart of the operationmethod of the management server according to a second exemplaryembodiment of the disclosure.

In the step S202, a request signal is received from a client, whereinthe request signal has a request number. In the step S204, the requestsignal is distributed to a sub-server according to the request number.In the step S206, a datum is obtained by the sub-server from a storageunit according to the request number, wherein the storage unit iscorresponding to the sub-server. In the step S208, the datum isoutputted according to the request number. In the embodiment, the datumstored in the storage unit is a portion of all data stored in a databaseof the management server and all data stored in the storages aredifferent.

FIG. 3 shows a flowchart of the operation method of the managementserver according to a third exemplary embodiment of the disclosure. Inthe step S302, a request signal is generated from a client, wherein therequest signal has a request number. In the step S304, the requestsignal is distributed to a sub-server according to the request number,wherein the storage unit is corresponding to the sub-server. In the stepS306, the request number is compared with a predetermined requestnumber, i.e. it is determined that whether the request number is equalto a predetermined request number.

When the request number is not equal to the predetermined requestnumber, the process returns to the step S302, the request signal isreceived from the client to perform the following process. When therequest number is equal to the predetermined request number, the processgoes to the step S308, the datum is obtained by the sub-server from thestorage unit according to the request number. In the step S310, thedatum is outputted according to the request number. In the embodiment,the datum stored in the storage unit is a portion of all data which arestored in a database of the management server and all data stored in thestorages are different.

FIG. 4 shows a schematic diagram of the server system according to afourth exemplary embodiment of the disclosure. The server system 400includes a plurality of clients 410_1˜410_M and a management server 420,wherein M is a positive integer greater than 1.

Each of the client 410_1˜410_M may generate a request signal, whereinthe request signal has a request number. Each of the client 410_1˜410_Mmay include a plurality of request numbers, and each of the requestnumbers may be, for example, a unique identification (UID) which formedas MAC address or formed as random string by English words, numerals orsymbols. Additionally, each of the client 410_1˜410_M may be, forexample, a mobile phone, a computer or any hardware device equipped withnetwork function, such as smart appliance or wearable device.

The management server 420 includes a plurality of storage units 430_1 to430_N, a plurality of sub-servers 440_1 to 440_N and a load balancingunit 450, and N is n positive integer greater than 1. The managementserver 420, the storage units 430_1 to 430_N, the sub-servers 440_1 to440_N and the load balancing unit 450 are respectively the same as orsimilar to the management server 100, the storage units 110_1 to 110_N,the sub-servers 1201 to 120_N and the load balancing unit 130 as shownin FIG. 1 and may be referred to the description of the embodiment inFIG. 1, and the description is omitted.

Additionally, the load balancing unit 450 is, for example, connected tothe client 410_1 to 410_M through the internet, bluetooth or otherconnection manners, so as to receive the request signals generated bythe client 410_1 to 410_M and distribute the request signals, such thatthe corresponding sub-server 440_1 to 440_N perform the followingprocess. In one embodiment, the management server 420 may further outputthe datum, obtained by the sub-servers 440_1 to 440_N from the storageunit 430_1 to 430_N, to the corresponding client 410_1 to 410_M throughthe load balancing unit 450 according to the request number. Or, inanother embodiment, the management server 420 may output the datum tothe client 410_1 to 410_M by itself through the corresponding sub-server440_1 to 440_N. Therefore, the efficiency of the system is balanced anda time for searching the data is decreased.

Additionally, the sub-servers 440_1 to 440_N may also compare therequest number with the corresponding predetermined request number so asto determine whether the request number is legal. The above-mentionedcomparing manner may be referred to the embodiment of the sub-servers120_1˜120_N in FIG. 1 and the description is omitted. Therefore, theefficiency of the management server 420 decreased by the request signalwhich is not legal may be avoided.

In the embodiment of FIG. 4, the quantity of the sub-servers 440_1 to440_N and the storage units 430_1 to 430_N is greater than one, and itis not limited to the disclosure. The quantity of the sub-server and thestorage unit may also respectively be one, and the embodiment of thesub-server and the storage unit may be referred to the above-mentioneddescription, and the description is omitted.

Additionally, the quantity of the request signal and the request numberthereof and the predetermined request number is one, and it is notlimited to the disclosure. The quantity of the request signal and therequest number thereof and the predetermined request number may also betwo or more than two. For example, when the quantity of the requestsignal and the request number thereof is two, the quantity of thepredetermined request number should be two. When the quantity of therequest signal and the request number thereof is three, the quantity ofthe predetermined request number should be three. The other embodimentsare similar to the previous ones, and the description may be referred tothe previous embodiment. Furthermore, when the quantity of the requestsignal is two, the two request signals may be outputted by the differentclients. The other embodiments are similar to the previous ones, and thedescription may be referred to the previous embodiment. The embodimentsof two or more than two the request signals and the request numbersthereof and the predetermined request numbers may be referred to thedescription of the above-mentioned embodiment, and the description isomitted.

Moreover, the request signal may has, for example, one request number,and it is not limited to the disclosure. The request signal may alsohas, for example, two or more than two request numbers at the same time.The quantity of the request number may correspond to the quantity of thepredetermined request number. For example, when the quantity of therequest number is two, the quantity of the predetermined request numberis two. When the quantity of the request number is three, the quantityof the predetermined request number is three. The other embodiments aresimilar to the previous ones, and the description may be referred to theprevious embodiment. The embodiments of the request signals includingtwo or more than two request numbers at the same time may be referred tothe description of the above-mentioned embodiment, and the descriptionis omitted.

FIG. 5 shows a schematic diagram of the server system according to afifth exemplary embodiment of the disclosure. The server system 500includes a plurality of clients 510_1 to 510_M and a pluralitymanagement servers 520_1 to 520_P, wherein M and P are a positiveinteger greater than 1. In the embodiment, the clients 510_1 to 510_M inFIG. 5 are the same as or similar to the clients 410_1 to 410_M and theoperation of the clients 510_1 to 510_M may be referred to thedescription of the embodiment in FIG. 4 and the description is omitted.

Additionally, the management servers 520_1 to 520_P and internalelements and the related operation thereof are the same as or similar tothe management server 420, and the operation of the management servers520_1 to 520_P may also be referred to the description of the embodimentin FIG. 4 and the description is omitted.

In the embodiment, the management servers 520_1 to 520_P may be, forexample, disposed in different places or countries. For the convenienceof description, the following description only uses, for example, theclient 510_1. The other embodiments of the clients 510_2 to 510_M aresimilar to the previous ones, and the description may be referred to theprevious embodiment. The client 510_1 may generate the request signaland transmit this request signal to the management server 520_1 to 520_Pat the same time. The management server 520_1 to 520_P obtains the datumcorresponding to the request signal according to the request number.Then, the client 510_1 may receive the datum from one of the managementserver 520_1 to 520_P which is the quickest response, and perform thefollowing process. Therefore, the datum requested by the client may besearched effectively and quickest.

Additionally, the sub-servers of the management server 520_1 to 520_Pmay connect to the database periodically or non-periodically so as toupdate the datum stored in the storage units of the management servers520_1 to 520_P at any time. Or, when a new data is added or updated indatabase, the sub-servers of the management server 520_1 to 520_P mayconnect to the database immediately so as to update the datum stored inthe storage units of the management server 520_1 to 520_P at any time.The data stored in the storage units of the management servers 520_1 to520_P are the same. For example, the data stored in the storage units430_1 of the management servers 520_1 to 520_P are the same. The datastored in the storage units 430_2 of the management servers 520_1 to520_P are the same. The other embodiments are similar the previous ones,and the description may be referred to the previous embodiment.

According to the management server and the operation method thereof andthe server system of the above-mentioned embodiments, the load balancingunit distributes the request signal to the corresponding sub-serveraccording to the request number of the request signal, such that thesub-server obtains the datum from the corresponding storage unit, andthen the management server outputs the datum from the correspondingstorage unit according to the request number (i.e. through the loadbalancing unit or the sub-server). Therefore, the quantity of theconnection may be balanced to balance an efficiency of the system anddecrease the time for searching the data. Additionally, the sub-serverfurther compares the request number with the predetermined requestnumber to determine whether the request signal is legal. Therefore, anefficiency decrease of the management server related to an illegalrequest signal can be avoided.

Although the disclosure has been explained in relation to its preferredembodiment, it does not intend to limit the disclosure. It will beapparent to those skilled in the art having regard to this disclosurethat other modifications of the exemplary embodiments beyond thoseembodiments specifically described here may be made without departingfrom the spirit of the invention. Accordingly, such modifications areconsidered within the scope of the invention as limited solely by theappended claims.

What is claimed is:
 1. A server system, comprising: a client, generatinga request signal, wherein the request signal has a request number; and amanagement server, comprising: a plurality of storage units,respectively storing a datum, the datum stored in each of the storageunits is a portion of all data which are stored in a database of themanagement server; a sub-server, corresponding to the storage units andconfigured to obtain the datum from the storage unit in response to therequest signal; and a load balancing unit, operatively connected to theclient and coupled to the sub-server, the load balancing unit beingconfigured to receive the request signal from the client and distributethe request signal to the corresponding sub-server in response to therequest number; wherein, the management server outputs the datumobtained by the sub-server from the storage unit according to therequest number; comparing the request number with a predeterminedrequest number; obtaining the datum by the sub-server from the storageunit according to the request number when the request number is equal tothe predetermined request number; and returning to the step of receivingthe request signal when the request number is not equal to thepredetermined request number.
 2. The server system as claimed in claim1, wherein the sub-server compares the request number with apredetermined request number to obtain the datum from the storage unitaccordingly.
 3. The server system as claimed in claim 1, wherein thesub-server is connected to the database to update the datum stored inthe storage unit.
 4. The server system as claimed in claim 1, whereinthe management server outputs the datum to the client through the loadbalancing unit or the sub-server.
 5. A management server, comprising: aplurality of storage units, respectively storing a datum, the datumstored in each of the storage units is a portion of all data which arestored in a database of the management server; a sub-server,corresponding to the storage units and configured to obtain the datumfrom the storage unit in response to a request signal, wherein therequest signal is generated by a client and the request signal has arequest number; and a load balancing unit, coupled to the sub-server,the load balancing unit being configured to receive the request signalfrom the client and distribute the request signal to the correspondingsub-server in response to the request number; wherein, the managementserver outputs the datum obtained by the sub-server from the storageunit according to the request number; comparing the request number witha predetermined request number; obtaining the datum by the sub-serverfrom the storage unit according to the request number when the requestnumber is equal to the predetermined request number; and returning tothe step of receiving the request signal when the request number is notequal to the predetermined request number.
 6. The management server asclaimed in claim 5, wherein the sub-server compares the request numberwith a predetermined request number to obtain the datum from the storageunit accordingly.
 7. The management server as claimed in claim 5,wherein the management server outputs the datum through the loadbalancing unit or the sub-server.
 8. An operation method of a managementserver, comprising: receiving a request signal from a client, whereinthe request signal has a request number; distributing the request signalto a sub-server in response to the request number; obtaining a datum bythe sub-server from a storage unit in response to the request number,wherein the storage unit corresponds to the sub-server; and outputtingthe datum according to the request number, wherein the datum stored inthe storage unit is a portion of all data which are stored in a databaseof the management server; comparing the request number with apredetermined request number; obtaining the datum by the sub-server fromthe storage unit according to the request number when the request numberis equal to the predetermined request number; and returning to the stepof receiving the request signal when the request number is not equal tothe predetermined request number.